Towards an environmental history of the eastern red river delta, vietnam

abandon-The Red River Delta in Vietnam is divided into three parts: the dominated mid delta, where the capital Hanoi is located; the tide-dominated eastern plain, centred at Hải Dương

өۣۣ۫ۢ۠ٷۘۙۘڷۚۦۣۡڷۜۨۨۤۃҖҖ۞ۣ۩ۦۢٷ۠ۧғۗٷۡۖۦ۝ۘۛۙғۣۦۛҖۑٮۆۃڷٲێڷٷۘۘۦۙۧۧۃڷڽҢڼғھڼڿғھڿڼғھۀڿڷۣۢڷھۀڷۑۙۤڷھڼڽۀ

Towards an environmental history of the eastern Red River Delta, Vietnam, c.900–1400

in Chu Đậu, deserting their main port, Vân Đồn, and for the Chinese ing a historical maritime invasion route.

abandon-The Red River Delta in Vietnam is divided into three parts: the dominated mid delta, where the capital Hanoi is located; the tide-dominated eastern plain, centred at Hải Dương (hereafter the easterndelta); and finally, the wave-dominated southeastern plain, where the cur-rent course of the Red River is, centred at Nam Đi ̣nh (hereafter the westerndelta).1Up to the tenth century, most of the sub-prefectures under Chineserule were located in the upper eastern delta and the upper-mid delta.This coastal area had been important to Jiaozhi (one of the names used

fluvial-by China for Vietnam) under Chinese rule (second century BCE to early

Li Tana is a Senior Fellow at the School of Culture, History and Language, College of Asia and Pacific Studies, the Australian National University Correspondence in connection with this article should be addressed to: tana.li@anu.edu.au The author would like to dedicate this article to the late Professor Yumio Sakurai, who significantly advanced our knowledge

of the socioeconomic and environmental history of the Red River Delta.

1 Susumu Tanabe, Kazuaki Hori, Yoshiki Saito, Shigeko Haruyama, Van Phai Vu and Akihisa Kitamura, ‘Song Hong (Red River) Delta evolution related to millennium-scale Holocene sea-level changes’, Quaternary Science Reviews 22, 21–22 (2003): 2348.

Journal of Southeast Asian Studies, 45(3), pp 315–337 October 2014.

© The National University of Singapore, 2014 doi:10.1017/S0022463414000319

tenth century CE) as well as independent Đại Việt, whose first capital for

41 years (968–1009 CE) was in Hoa Lư (Ninh Bình province) In 1010 thenewly founded Lý dynasty moved its capital to Đại La, the site of theTang Annam Protectorate office, today’s Hanoi, and renamed it ThăngLong (ascending dragon) Although the same city was adopted by theTang Annam protectorate and the Lý as their administrative centre,the Tang had regarded the eastern delta as crucial because Đại La linkedits capital Changan with the coast, while the Lý dynasty was a stronglyriverine polity

John Whitmore has drawn our attention to the multiethnic coastal area

of the early Đại Việt and its significance for Vietnamese history.2 Building

on his focus, this article situates the eastern coastal area of the RedRiver Delta within its natural environment to better understand howhuman actions and nature jointly shaped the region in the first four hun-dred years of Đại Việt’s independence, and their long-term impact onVietnamese history

Population in the Lý period

Although in the second century BCE northern Vietnam (Jiaozhi) wasthe most densely populated area in the Han Empire’s southern coast,3

the situation had changed dramatically by the tenth century The reasonsfor this were threefold First, as Michael Churchman shows, between thethird and sixth centuries Sinitic-speaking settlers were concentrated inkey centres in coastal-southern China, such as Nanhai (Guangdongcoast), Hepu (Guangxi coast), and Jiaozhi, while vast areas of present-dayGuangxi were inhabited by the Li and Lao, who spoke Kam–Tai languages.These non-Han chiefdoms largely cut off the much more ‘civilised’ Jiaozhifrom central China and, importantly, Han Chinese migration to Jiaozhi forover three hundred years.4Second, Guangdong’s economic position greatlyimproved in the eighth century with the opening of the Dayu Mountainroad and the linking of Guangzhou to the hinterland From the early eighthcentury onwards, an unprecedented abundance of goods flowed from thehinterland to Guangzhou for trade, eclipsing former rival Jiaozhi A thirdand equally important factor was that, by the ninth century, Persian andArab merchants — the new princes of the Nanhai trade — chose to sail

2 John K Whitmore, ‘The rise of the coast: Trade, state and culture in early Đại Việt’, Journal of Southeast Asian Studies 37, 1 (2007): 104–8.

3 Li Tana, ‘Jiaozhi (Giao Chi) in the Han period Tongking Gulf’, in The Tongking Gulf through history, ed Nola Cooke, Li Tana and James A Anderson, pp 39–52 (Singapore: Institute of Southeast Asian Studies, 2013).

4 Michael Churchman, ‘“The people in between”: The Li and Lao from the Han to the Sui’,

in Cooke et al., The Tongking Gulf through history, pp 67–83.

directly to Guangzhou on the open sea, cutting out Jiaozhi and many of itstrading partners down the coast.5 While the first factor greatly reduced theinward migration of the Han Chinese to Jiaozhi, the latter two factors mayhave encouraged outward migration from Jiaozhi In the ninth century, thecombined number of households in north and central Vietnam neverexceeded forty thousand, or less than half the regional total recorded atthe height of the Han period.6 By the time of its independence in thetenth century, Đại Việt was anything but densely populated.

The newly independent Đại Việt was largely governed by local strongmen, ‘big men’ whose status was determined, in part, by the number ofbonded people they managed to amass Next to trade, raids were themost effective means of obtaining manpower Slave raids were commonpractice among the people of Lingnan (southeastern China) and Annam.The Tang records are filled with descriptions of such raids, and the trade

in slaves belonging to different tribes in Guangdong, Hainan and larly Guangxi Manpower was as precious in tenth-century Guangxi as itwas in Jiaozhi Guangxi officials often quietly accepted the exodus ofViet people from Đại Việt, without turning them back This caused dis-putes and directly led to the Việt king Lê Hoàn’s raid of the Guangxicoast in 995.7 These accounts provide a context for Việt attacks on nearbyregions Raids were carried out throughout the Former Lê period (980–1009) which preceded the Lý dynasty:

particu-982: Lê Hoàn ransacked Champa and captured ‘countless’ soldiers, several dred court ladies and one Indian monk.

hun-995: Lê Hoàn raided Qinzhou at the Guangxi coast and captured 113 men and women.

997: Lê Hoàn attacked the Hà Đông area (near present-day Hanoi), which had been occupied by the Ngô family, and returned with the captives.

1008: In attacking the Tai-speaking peoples in the Tuyên Quang area, Lê Hoàn’s son captured a few hundred people and horses.

1008: Attack on Nghệ An with captives taken 8

5 Paul Pelliot, ‘Deux itinéraires de Chine en Inde a la fin du VIIIe siècle’, Bulletin de l’École française d’Extrême-Orient 4 (1904): 133.

6 Yuanhe qunxian zhi [Prefectures and districts in the Yuanhe period] (Beijing: Zhonghua shuju, 1980 [821]), pp 955–66.

7 Songshi, juan 384, ‘Chen yaosou zhuan’ [A biography of Chen yaosou], electronic edition

of the Wenyuange sikuquanshu [Complete library of four branches of literature].

8 Đại Việt sử ký toàn thư [Chronicles of the Great Viet, hereafter Toàn Thư] (Tokyo: Tokyo University, 1984), pp 189, 194, 195, 200, 210, 211 Việt sử lươ ̣c [A concise history of the Viet] (Hanoi: Văn sử đi ̣a, 1960) records that during the raid of Champa in 982 several hun- dred court ladies were captured, not just over a hundred, as claimed by Ngô Sĩ Liên in Toàn Thư, p 20.

Records of raids are not lacking for the Lý dynasty (1009–1225) either:

1044: King Lý Thái Tông attacked Champa and captured over 5,000 people and 30 elephants 9

1048: Lý Thái Tông attacked Ai Lao and obtained ‘many people and animals’ 10 1060: The emperor’s son-in-law, an official of Lạng Sơn Thân Thiều Thái, recap- tured the soldiers who had fled to the Song, together with ‘countless’ men, women, cattle and horses 11

1069: Attack on Champa, with the capture of King Chê´ Cự and 50,000 people 12 Chinese sources record that the Song emperor heard that the ‘majority of Cham households were captured by Jiaozhi’ 13

1075: Attack on the Guangxi coast: over 3,000 people from the three prefectures were captured and forced to enter Đại Việt 14 Only 221 of them were sent back in

1079 15

1119: Attack on Hoà Bình; the chief and ‘a few hundred people’ captured 16

The raids listed above were clearly aimed at treasure, horses, cattle, andmost importantly, people While some of the captives may have beensold around the region, most of them were used as court servants A mas-sive number of palaces, towers, gates, temples and pagodas were con-structed between the end of the tenth and twelfth centuries, at a timewhen the country was still underpopulated and manpower under directcourt control was even more limited.17 Song and Cham prisoners of warwere resettled around the Lý stronghold — the capital and the upperRed River Delta — where they became an important resource for courtbuilding projects.18 Vietnamese scholar Trần Quô´c Vượng points outthat Cham prisoners were used to build the main pagodas, towers androyal travel lodges The famous pagoda of the Lý period in Hanoi, ThápBáo Thiên, was built by Cham prisoners, and Cham inscriptions were

9 Toàn Thư, p 234.

10 Ibid., p 236.

11 Việt sử lươ ̣c, p 35.

12 Toàn Thư, p 245.

13 Zhongguo guji zhong de jianpuzhai shiliao [Sources on Cambodia in Chinese classics],

ed Chen et al (Zhengzhou: Henan renmin chubanshe, 1985), p 117.

14 Toàn Thư, p 248; also excerpt in Gudai zhongyue guanxishi ziliao xuanbian [Sources on Sino–Viet history] (Beijing: Zhongguo shehui kexue chubanshe, 1982), p 214.

15 Zhongguo guji zhong de jianpuzhai shiliao, p 224.

16 Toàn Thư, p 261.

17 Momoki Shiro points to the practice of raiding the Cham population and buying slaves from southern China and suggests that the population under Lý control was sparse, with small and scattered areas of cultivation Momoki Shiro, The formation and transformation

of the medieval state of Đại Việt: A Vietnamese history during the Lý–Trần period within regional histories (Osaka: Osaka University Press, 2011), p 90.

18 After the invasion of Champa in 1044, the Lý settled the Cham prisoners of the war in outlying areas of Hanoi, at Từ Liêm and Hòai Đức, as well as at Sôn Tây and Phú Thọ.

found on the bricks of the Lý royal palace, in the recently excavated ThăngLong citadel.19 Raids therefore went in tandem with the Lý’s constructionprojects Table 1shows the correlation between raids and court construc-tion between the tenth and twelfth centuries.

Given the shortage of manpower, the court guarded its bonded lation carefully; all were tattooed so that no other local strongmen couldclaim them When over 3,000 people from Guangxi were captured bygeneral Lý Thường Kiệt in 1075, men over 15 years old had ‘thiên tửquân’ (天子軍 ‘army of the son of the heaven’) tattooed on their foreheads;those over 20 were tattooed with ‘đầu nam triều’ (投南朝 ‘volunteered tothe South dynasty’, i.e the Lý); and women had ‘quan khách’ (官客 ‘officialguests’) tattooed on their left hands.20 While in general, bondsmen wouldhave three to four characters tattooed on their foreheads (for men), malecriminals who became court slaves were tattooed with six characters, and

popu-Table 1: Court construction projects and number of raids in Đ Đ ại Việt, 980–1210 CE

Source: Đại Việt sử ký toàn thư [Chronicles of the Great Viet] (Tokyo: Tokyo University, 1984).

19 For a photo of Cham inscriptions on Thăng Long citadel, see Phan Huy Lê, ‘Giá trì toàn cầu của khu di tích trung tâm hoàng thành Thăng Long-Hà Nội’ [The world value of the Thang Long-Hanoi citadel], in Selected Japanese–Vietnamese papers on the Thang Long Citadel (Tokyo: National Research Institute for Cultural Properties, 2012), p 129; there are Cham-style wells in several areas near Hanoi See Trần Quô´c Vượng, ‘Viet–Cham cul- tural contacts’, in Trần Kỳ Phương and Bruce M Lockhart, The Cham of Vietnam: History, society, and art (Singapore: National University of Singapore Press, 2011), pp 269–70 On settling Cham prisoners in Bình Lục district, see Yao Takao, ‘Landholding and opening by the generals who contributed to the founding of the Lê dynasty’, in Report on the project: The opening of the lower Red River Delta, ed Yao Takao, p 177, MS.

20 Wenxian tongkao [General study of the literary remains], juan 330, ‘Siyi kao 7’, http:// www.guoxue123.com/shibu/0401/01wxtk/333.htm (last accessed 20 June 2013).

women were tattooed with two Those who dared to try to flee were severelypunished by having some 50 characters tattooed on their faces, and receive

100 lashes.21This punishment contrasts with the rather more lenient ment of murderers: instead of the death penalty, the law allowed for theoffender to pay monetary compensation to the victim’s family.22 All thissuggests a shortage of manpower under the Lý

treat-The eastern delta under the Lý

The Lý dynasty was a local power and its territory was limited YumioSakurai points out that the Lý only directly controlled the capital and lowerwestern delta; Momoki Shiro further indicates that its strongholds were inThanh Hoá, Thái Nguyên and Sơn Tây Both scholars agree that the out-lying territories were semi-autonomous areas controlled by local powers.23

Whitmore places the Lý-controlled area at the ‘mid-river core of the delta’,and suggests that the Lý Đại Việt, like Angkor and Pagan, was focused onthe upper, mid-river portion of its territory, and paid little attention to thecoast.24 This largely leaves the eastern coast out of the map of the Lý.This is intriguing, as the eastern delta was where the most rapid growth ofthe Red River Delta occurred between the first and tenth century.25 Recentarchaeological findings indicate that between the seventh and ninth centuriesTuần Châu island in Quảng Ninh was a major ceramic production centre forthe Tang Annam Protectorate Tuần Châu is located on the waterway toChina, and the ceramics uncovered here are described as among some ofthe finest in Vietnamese history.26 The eastern delta and its coast wouldhave been the area where Annamese Middle Chinese (as termed by JohnPhan), was spoken.27 This language, as Keith Taylor points out, could be a

27 John Phan, ‘Re-imagining “Annam”: A new analysis of Sino–Viet–Muong linguistic tact’, Chinese Southern Diaspora Studies 3 (2010): 3–24.

con-dialect of a broader Southern or Southwestern Middle Chinese of the tenthcentury.28 There had likely been a strong Chinese community on the coast

of the eastern delta, according to Taylor This was where Khúc Thừa Dụ, arecently arrived Chinese immigrant, rose and declared himself governor ofAnnam in 906, an act that established the path for Vietnam’s independence.Khúc was from Ninh Giang prefecture, Hải Dương The eastern delta wasalso where Wu Hun (Vũ Hồn in Vietnamese), a protector-general in the840s, had settled.29 The Vũ family became the most prominent family inMộ Trạch, Hải Dương, producing many scholar-officials in the Trần and

Lê periods The family genealogy boasts three government ministers andeighteen doctoral students (tiê´n sĩ).30 Interestingly, none of the Vũ familymembers served in the Lý court in the first two centuries of Đại Việt’s inde-pendence How do we explain this gap?

The elite living on the eastern coast was likely excluded from the Lýcircle, if we use the Thơ văn Lý Trần (a literary anthology of the Lý andTrần period) as a ‘Who’s Who’ during the four centuries of Lý and Trầnrule Out of the 26 people listed under the Lý, only two, both monks,were from the eastern delta The place of origin of the elite changed com-pletely in the Trần era (1225–1400): 29 of the 35 people listed were fromthe eastern delta.31This striking change strongly suggests that the Trần rul-ing base was at the coast, particularly in the east

Whitmore asks how ‘the region to the East — downriver, the lowerdelta, the coast — fit into the Lý regime’? Answering his own question,

he provides an important insight: ‘It does not appear to have been ofvery great significance and possibly was of different ethnicity’.32 But ifthe eastern coast was where the overseas trade took place, and the wealthwas, why did the Lý not tap into the resources of this area instead of aban-doning it to other ethnicities? Here is a hint from the Việt chronicles:

During the Lý dynasty, when the ships from China came to visit they had used the seaports of Diê˜n Châu [Nghệ An] and Tha Viên [unidentified location] as entry

28 Keith Taylor, A history of the Vietnamese (Cambridge: Cambridge University Press, 2013), p 5.

29 Keith W Taylor, The birth of Vietnam (Berkeley: University of California Press, 1983),

pp 217, 260.

30 ‘The Vũ family in Mộ Trạch’, in Nantian zhenyiji [Nam Thiên Chân di ̣ tập in Vietnamese], Yuenan Hanwen xiaoshuo jicheng [Collections of the Vietnamese novels in Han script] (Shanghai: Guji chubanshe, 2010), vol 10, pp 140–41.

31 These figures exclude the Lý and Trần royalty The birthplaces of some authors are not vided, and they are therefore also excluded Thơ văn Lý-Trần [Poetry and essays of the Lý-Trần periods], 3 vols (Hanoi: Nhà xuâ´t bản Khoa học xã hội, 1977–1978) Two writers whose poems were included came from Fujian, in the twelfth and thirteenth century, respectively.

pro-32 Whitmore, ‘The rise of the coast’: 107.

points Since then [1148] the sea routes had changed and the seaports became dry and shallow, [therefore merchants] tended to gather at Vân Đồn, and this was why [the court] ordered them to set up [the government offices] there 33

This source indicates that the Lý’s major ports were at the central coast next

to Champa, not the eastern coast, next to Guangxi, and that this shift toVân Đồn was caused by environmental changes in the central coast inthe mid twelfth century Between the tenth and twelfth centuries the east-ern coast was probably a stretch of wilderness, largely left to outsiders,including Sino–Viet descendants such as the Vũ family, Tai speakers,recent migrants from Fujian, and Vietnamese and Dan fishermen.34

Quang Ninh, the province bordering Song China, was where fishermenand traders indiscriminately colluded with refugees, smugglers, banditsand pirates.35 James Anderson observes that the Lý pulled back from theearlier Hoa Lư coastal links and focused on the montane trade in the elev-enth century This was perhaps partly because the Northern Song wasfocused on northern affairs and thus little commerce was carried out inthe Gulf of Tongking area It was also partly due to the fact that the Lý’spolitical control was limited, and thus they had no power base in thisarea As Anderson points out, along the Gulf of Tongking coast, people

at the margins of both kingdoms ‘had for centuries continued to makelocal alliances and local deals in their own interests that largely ignoredcentral authorities’.36

At almost the same time that the Lý’s major port in central Vietnamsuffered from siltation, events in China exerted an influence on the region.The Guangxi coast, which had been half-deserted following the collapse ofthe Tang dynasty, enjoyed a sudden boom in commodity exchange.Because of the urgent need for horses for its military, the Southern Song(1127–1279) allocated a huge amount of its annual budget to the horsetrade in the Yunnan–Guangxi–Đại Việt border area This horse tradespurred regional growth through stimulating trade, and created a commod-ity exchange system within the Jiaozhi Sea (Gulf of Tongking) area.37

33 Toàn Thư, p 424 The Vân Đồn garrison, prefecture and sea patrol offices as well as the Bình Hải (Sea Pacifying) navy were only set up in 1349, almost two hundred years after the port officially opened.

34 James Anderson, ‘“Slipping through holes”: The late tenth and early eleventh-century Sino–Vietnamese coastal frontier as a subaltern trade network’, in Cooke et al., The Tongking Gulf through history, pp 94–5.

35 Robert Antony, ‘Violence and predation on the Sino–Vietnamese maritime frontier, 1450–1850’, Asia Major (forthcoming).

36 Anderson, ‘“Slipping through holes”’, p 93.

37 See Li Tana, ‘A view from the sea: Perspectives on the northern and central Vietnamese coast’, Journal of Southeast Asian Studies 1, 37 (2006): 83–102.

Chinese migration in response to the commercial boom in this regionwould have contributed considerably to population growth in Đại Việt inthe twelfth century The magnitude of this growth is visible in a detailedreport on voluntary and forced migration into the Lý Đại Việt by aGuangxi official named Fan Chengda in 1170s:

Moreover, the indigenes of their country form much less than half [of the tion] [There are] people of [our] territory [who] travel to the south [and] entice people, male and female, to become menials [They] grab them and take them into the mountain grottoes of [this] territory, binding and selling them for two liang of gold [From this] territory’s grottoes, [they] move and sell them into Jiaozhi [Ðai Viet], receiving three liang of gold (for each one) Yearly, there are not less than 100,000 [such people]…

popula-There are also accomplished scholars, Buddhist monks, Daoist practitioners, and clever artisans, [all] becoming absconders [who] have lost the [imperial] man- date Those who flee are very many… [The Vietnamese thus] grab and plunder the sold men and women as well as the scholars [who] cross the frontier and enter [their land] 38

The statement that Vietnamese formed much less than half the lation of the entire Đại Việt is of course an exaggeration Yet, asWhitmore points out, Fan ‘was looking at the country through the coastalprism of the Lower Delta, and so his words make sense mainly forthis area, the one with which the Chinese would have had the most con-tact and familiarity’.39 It is no coincidence that the port of Vân Đồn wasopened in 1148, only two decades after the founding of the SouthernSong dynasty.40 The Chen family (later to become the Trần imperialfamily) might have arrived at the eastern coast around this time, ifnot earlier According to Trần Quô´c Vươ ̣ng, the Trần had wanderedaround the eastern coast before moving to Thiên Trường.41 The factthat the huge ancestor temple (Đền Thái) complex of the Trần royalfamily is situated in Đông Triều district, Quảng Ninh, confirms this

popu-38 Fan Chengda’s report, ‘Guihai Yuhengzhi’, is included in Ma Duanlin’s Wenxian kao [General study of the literary remains] (Shanghai: Shangwu yinshuguan, 1936), pp 2593–5 (quotation, p 2594) The English translation is by J.K Whitmore in ‘Brush and ship: The southern Chinese diaspora and literati in Đại Việt during the 12th and 13th cen- turies’, Chinese Southern Diaspora Studies 4 (2010): 38–9.

tong-39 John Whitmore, ‘The fate of the Ngô: Montane/littoral division in 15th–16th century

Đ ại Việt’, paper presented at the conference ‘Maritime frontiers in Asia: Indigenous nities and state control in South China and Southeast Asia, 2000 BCE–1800 CE,’ Pennsylvania State University, Apr 2013, p 5.

view.42 The Quảng Ninh–Hải Dương area (particularly Đông Triều andChí Linh districts) saw a concentration of the estates of the leading Trầnprinces, eight of whom were crowded on this limited strip The flourishingcommerce on the northeastern coast would have attracted migration fromthe upper Red River Delta,43 from where many of the Trần elite came.Momoki Shiro observes that many famous officials such as Trần Khă´cChung and Phạm Sư Mạnh came from Quảng Ninh and Hải Dương andthat the Trần ‘relied heavily on the rule of such regions as the easternedge of the delta, the lower delta and the southern provinces, where notonly trade thrived but agricultural reclamation advanced remarkably’.44

The ethnic intermingling and integration on the northeast coast led to

a new stage in the interaction of Northerners and Southerners (Chinese andVietnamese) As Whitmore points out, the maritime dimension facilitated

by the intensive interactions with the Chinese and Song culture, led to aboom in the literati in this area.45

Population boom in the Trần period

Independent Đại Việt emerged during favorable climatic conditionswhich lasted for about three hundred years Data reconstructed from thetree-ring widths of cypresses in southern Vietnam indicates that between

900 and 1250–1300, Southeast Asia enjoyed unusually warm, La like conditions, which tended to produce greater annual volumes of rainfall,longer monsoons and shorter dry seasons.46This was particularly helpful tothe success of the rice crop in the Red River Delta during the Lý and Trầnperiods On the newly reclaimed land along the coast the fifth-month riceharvest (lúa chiêm) was critical to the population’s survival,47 but was

Niña-42 Tô´ng Trung Tín et al., ‘Di tích Đền Thái qua tư liệu khảo cổ học’ [Archaeological data of the temple of ancestors], Khảo cỏ học [Vietnam Archaeology] 5 (2011): 5–22 The article points outs that An Sinh was the original homeland (quê hương, quê gô´c) of the Trần See

pp 20–21.

43 Di dân của người Việt từ thệ kỷ X đê´n giu˜̛a thê´ kỷ XIX [Vietnamese migrations from the 10th to the 19th centuries], ed Đặng Thu (Hanoi: Phụ san Nghiên cứu li ̣ch sử, 1994), pp 36–7.

44 ‘Trần Khác Trung, Phạm Sư Mạnh and other famous officials all came from the eastern edge of the delta, such as Mạc Đĩnh Chi in Nam Sách, Đoàn Như Hài in Gia Lộc, Nguyê˜n Trung Ngạn from Khoái Châu’, all in Hải Dương Momoki Shiro, ‘Main points on the his- tory of cultivation of the lower Red River Delta in the Lý and Trần period’, in Yao Takao,

‘ Report on the project: The opening of the lower Red River Delta’, p 19.

45 Whitmore, ‘Brush and ship’: 40–41.

46 Victor Lieberman and Brendan Buckley, ‘The impact of climate on Southeast Asia, circa 950–1820: New findings’, Modern Asian Studies 46, 5 (2012): 16.

47 Momoki Shiro, ‘Mâ´y luận điểm mới về li ̣ch sử khai phá vùng hạ lưu châu thổ sông Hồng trong giai đọan Lý–Trần: (I) Hệ thô´ng hành cung thời Lý’ [Some new insights into the his- tory of opening of the lower Red River Delta during the Ly and Tran periods], paper for

vulnerable to droughts in spring Three centuries of stable rain-fed harvestswould have greatly encouraged the expansion of land cultivation and sti-mulated fertility These favorable ‘wet centuries’ thus helped to jump-startthe charter state expansion of the time, that saw so many well-organised,new kingdoms flourish.48 The rapid growth of the eastern delta occurredwithin this broad background, contemporaneous with the golden age ofAngkor and Pagan In all three cases, as Victor Lieberman points out, a per-iod of greatly enhanced rainfall accelerated cultivation, construction andpopulation growth.49

Đại Việt’s population doubled to three million between 1200 and 1340,according to Sakurai.50 By the mid fourteenth century the average popula-tion density of the delta was 150–180 people, and one to two villages, persquare kilometre.51The population density in the northeastern delta wouldhave been higher than this average, judging from the early fifteenth centurydata (see below) There is no data to gauge the extent of Chinese migration

to Đại Việt in the twelfth century, but the Lý’s recorded raiding stopped inthe late twelfth century, suggesting that Chinese migration and raiding mayhave been somewhat correlated This was also a period of Chinese migra-tion into other parts of Southeast Asia in ‘a continuous flow’, as pointed out

by Anthony Reid.52Whitmore notices that in this period, draining and dering were carried out in both south China and the lower delta of ÐaiViệt This led to agricultural intensification and, together with growingcommerce, a greater concentration of population and wealth in this area.Owing to this rapid growth, by the thirteenth century, land had becomescarce

pol-This explains why the Trần court issued a somewhat desperate plea in

1266 that the aristocracy, all ‘princes, princesses, king’s son-in-laws andcourt ladies’, gather ‘landless and drifting’ people to become their slaves

conference ‘Vietnamese studies in Vietnam: Contemporary situation, achievements and directions’, 2005, Hanoi, p 1.

48 Lieberman and Buckley, ‘Impact of climate on Southeast Asia’: 17.

49 Victor Lieberman, ‘Charter state collapse in Southeast Asia, ca 1250–1400, as a problem

in regional and world history’, American Historical Review 116, 4 (2011): 947.

50 Yumio Sakurai, ‘Age of commerce’, MS, cited in Lieberman, Strange parallels: Southeast Asia in global context c.800–1830 (Cambridge: Cambridge University Press, 2003), vol 1,

p 368.

51 Lieberman, Strange parallels, p 368.

52 Anthony Reid, ‘Flows and seepages in the long-term Chinese interaction with Southeast Asia’, in Sojourners and settlers: Histories of Southeast Asia and the Chinese, ed Anthony Reid (St Leonard’s: Allen & Unwin, 1996), p 17; see also Geoff Wade, ‘Southeast Asian Islam and Southern China in the fourteenth century’, in Anthony Reid and the study of the Southeast Asian Past, ed Geoff Wade and Li Tana (Singapore: Institute of Southeast Asian Studies, 2012), pp 129–30.